Computer Graphics Error

I'm not sure why, but my computer screen from time to time will start to show yellow, black, gray, and white lines in one area, like "start" and when I click it will sudently show more lines, and I can't see anything. It sometimes goes away when I turn my computer off, but not always.This just sudenly started happening and I have no idea why. This computer is less then half a year old.

Is there any suggestion for me to solve that error? Thanks in advance.